The present invention relates to an improved cooling apparatus for vehicles, especially for passenger motor cars of the type having at least one cooler extending transverse to the driving direction. The present invention is particularly related to an arrangement for the guidance of the cooling air supplied to the coolers. It will be understood that these coolers are of the type which include a fluid medium, such as engine coolant and/or lubricating oil, which passes in heat exchanging relationship with respect to the cooling air.
A motor vehicle has been contemplated (FR-PS 1075 582) which is provided with a cooler in the nose or front portion and which includes a cooling air guide arrangement. The air guide arrangement in this vehicle is constructed with a channel forward of the cooler and an opening arranged at the topside of the vehicle provided with a flap. However, this arrangement has the disadvantage that the nose space construction, which accommodates the channel passage, is such as to make it difficult to also accommodate housing of aggregates and provisions of a luggage and/or engine space. Further, by changing the direction of the air stream to the opening at the vehicle topside, the internal air resistance and therewith also the driving resistance acting on the vehicle is increased.
The present invention contemplates overcoming the above-mentioned disadvantages by providing an arrangement for the guidance of the cooling air admitted to the coolers so as to produce a minimum amount of air resistance and so as not to impair the utilization of the nose space of the vehicle for storage and engine compartments and the like. The present invention further contemplates arranging the air inlet for the cooler entirely below a forward bumper of the vehicle, with the further provision of simple air deflecting means for optimizing the velocity distribution of the cooling air at the inlet side of the respective coolers. In preferred embodiments of the invention, the cooler or coolers are arranged in an inclined position with the bottom side of the cooler arranged forwardly of the topside thereof so as to maximize the cross section of the inlet to the cooler, while minimizing the vertical space taken up in the vehicle nose section. In conjunction with this inclined cooler arrangement, air guide devices are provided for equalizing and optimizing the distribution of cooling air over the inlet side of the coolers.
The present invention further contemplates provision of air guide devices which effect an air distribution at the side of the cooling air entrance and a vacuum at the cooling air exit side, which vacuum is a function of the vehicle driving velocity. In particular preferred embodiments, the air guide devices for the air exit side extend below the cooler and essentially perpendicular to the driving direction of the vehicle. This air guide device at the exit is arranged or attached at a lower closure wall of the vehicle body and is configured so as to assure a speed up in the air flowing thereby so as to create the vacuum effect at the exit side of the cooler.
In preferred embodiments, the air guide devices at the cooling air entrance side of the coolers are constructed so as to have a plurality of compartments of separated flow paths. These compartments are shaped such that the cooling air discharged therefrom to the inlet surface of the cooler is distributed appropriately over the surface of the cooler. In a particularly preferred embodiment, these compartments are formed by a common air inlet device inserted between the bottom wall of a storage compartment and the bottom wall of the vehicle body and adjacent and slightly rearward of a forward bumper of the vehicle.
In preferred embodiments with the coolers inclined downwardly in the forward direction, the coolers are directly attached at a lower closure wall of the vehicle body. In other preferred embodiments with a vertically extending cooler, a partition is provided between the lower enclosure wall and the cooler for closing off the space between the lower enclosure wall and the cooler and for accommodating attachment of a vertically extending cooler and a similar body construction as for the inclined coolers.
In preferred embodiments, two separate cooling units are arranged one behind the other in the driving direction with the front cooler being constructed substantially smaller in height than the rear cooler and covering essentially the lower region of the rear cooler. In these preferred embodiments, the air inlet guide devices are constructed so as to direct a greater portion of the inlet air to the lower portion of the cooler than to the upper portion.
Preferred embodiments of the invention also include an upwardly extending opening at the air entrance side, which upwardly extending opening, in conjunction with adjacent vehicle bumper and hood parts, creates a vacuum suction effect during driving of the vehicle.
The cooling apparatus arrangements of the present invention all exhibit advantages with respect to the guidance of the cooling air into communication with the cooler or coolers. The deflecting arrangement at the bottom of the vehicle for producing a vacuum at the exit side of the coolers assures the smooth conductance away of the cooling air from the coolers. Since the air guide device for creating the vacuum at the exit side of the coolers is formed by a simple part provided at a lower closure wall of the vehicle body which extends perpendicularly to the driving direction of the vehicle, the construction thereof is particularly economical and reliable. By providing that the air inlet guide devices are arranged exclusively below the bumper, a good distribution of the free air stream in front of the vehicle into the coolers is obtained. With the cooling air entrance being disposed below the bumper, with the inlet velocity distribution being varied over the vertical height thereof as a function of the predetermined mounting height of the bumper and the predetermined batter angle (angle from the point of contact of the vehicle wheels to the deflecting edge underneath the cooler at the exit side thereof), a particularly advantageous controlled design for the cooling apparatus can be provided by appropriate selection of the height of the cooler. In this connection, it is noted that the variable velocity distribution at the inlet disposed underneath the bumper is such that a higher velocity air is provided to the lower portion of the cooler. To maximize utilization of this phenomenon with higher velocity air in the lower portion of the cooler, two coolers of different size are arranged one behind the other in the direction of driving, in accordance with preferred embodiments of the invention. In these last-mentioned preferred embodiments, the front cooler is advantageously made smaller than the rear cooler so as not to obstruct the upper portion of the rear cooler.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.